From: Development of an algorithm for determining smoking status and behaviour over the life course from UK electronic primary care records
WHS
Totals
GP
Missing data
smoker
Ex-smoker
Never smoker
<5
89
120
199
413
Smoker
17
1040
426
209
1692
34
130
1449
1104
2717
16
42
186
1770
2014
72
1301
2181
3282
6836